Spark plug



` L. HIRSCH SPARK PLUG Filed July 26, 1924 WITNESSES 1N VEA/TOR,

i l ATTORNEYS.

Patented Nov. 3, 1925.

UNITED .STATES LoUIs mason, or MESILLA rank, NEW i/Lnxroo.

sriinx PLUG.

Application led July 2, 1924. Serial 110.728,414. i

To all whom t may concern.'

Be it known that I,-LOU1s HIRsoH, a citi- Zen of the United States, anda resident of Mesilla Park, in the county of Dona Ana and State of NewMexico, have invented a new and Improved Spark Plug, of which thefollowing is a full, clear, and exact description.

This invention relates to improvements in spark plugs, an object of theinvention being to provide a plug having four electrodes providing apair of spark gaps normally arranged in series and capable of connectionwith any desired electric circuit.

A further object is to provide a plug of the character stated in whichone of the electrodes may be moved so as to open the normal circuit andprovide a spark gap between the same and the plug casing through whichlatter the circuit is grounded.

A further object is to provide a plug of the character stated, in whichthe casing may remain fiXed to the engine cylinder and a removable shellfixed thereto and carrying the core and operative parts can be re movedand replaced at will.

With these and other objects in view, the invention consists in certainnovel features of construction and combinations and arrangements ofparts which will be more fully hereinafter described and pointed out inthe claims.

In the accompanying drawings- Figure 1 is a perspective view illustrateing my improved spark plug;

Figure 2 is a view in longitudinal section through the plug;

Figure 3 is a view in transverse section on the line 3-3 of Figure 2;

Figure 4 is an inner end view of the plug.

1 represents the casing of my improved plug which is externallyscrew-threaded at its inner end, as shown at 2, and adapted to besecured in an engine cylinder, and it is to be understood that thiscasing l may remain in the cylinder and the other portions of the plugremoved and replaced at will. The upper end of the casing 1 is somewhatenlarged transversely and provided with internal screw threads 3 toreceive the eX- ternally threaded lower end of a shell 4, the latterhaving a ground joint connection, as indicated at 5, with the casing 1to render the connection gas tight. This shell 4 receives ascrew-threaded nut 6 which functions to clamp the core 7 in the shell.The

core 7 has an annular enlargement 8 with a washer 9 interposed betweenthe same and the inner end of the shell, and a washer 10 interposedbetween the enlargement 8 and the nut 6. The core 7 supports fourelectrodes 11, 12, 13 and 14, which extend through the core and areprovided at their inner ends with terminals 15 positioned at rightangles to the electrodes. It will be noted that these terminals arespaced apart forming a pair of spark gaps. The electrode 11 has rotarymounting or partial rotary mounting in core 7 and is connected by aconductor 16 with the distributor of the en- 70 gine. A crank arm 17 isfixed to the electrode 11 and may be connected by a rod 18 with anyconvenient operating device at the dashboard of the car. The turningmovement of the electrode is limited by an arm 19 fixed thereto andengaging a stop or plug 20 on the core. The electrodes 12 and 13 areconnected by a link or other form of electric conductor 21 and thenormal circuit is as follows: from the distributor to from the wall ofthe casing 1 so as to form 90 a spark gap between said terminal and thecasing. This movement of the electrode 11 opens the circuit as abovedescribed and provides a spark gap between the same and the casing 1,which circuit is grounded in the ordinary way.

Various slight changes and alterations might be made in the general formof the parts described without departing from my invention, and hence Ido not limit myself to the precise details set forth but consider myselfat liberty to make such slight changes and alterations as fairly fallwithin the spirit and scope of the appended claims.

I claim:

1. A sparkplug, comprising a casing, a core in the casing, fourelectrodes in the core providing two spark gaps at their inner ends, andall of said electrodes connected in series, one of said electrodesmovablev to open the normal circuit and provide a spark gap between thesame and the casing.

2. A spark plug, comprising a easing, a core in the easing, an electrodein the easing mounted t0 turn, a terminal on the inner end of theelectrode at an angle thereto, :L

i? second electrode in the core having a terminal at its inner end, andsaid irst-Inen-v tioned elect-rode adapted to he turned to form a sparkgap with the other electrode or With the casing.

3. A spark plug,`eomprising e easing, a,

shell removably secured therein, a core removably secured in the shellbut removable from the casing with the shell, four electrodes located inthe core and extending therethrough, said electrodes providing a pair ofspark gaps at their inner ends, and

one of said electrodes movable to a position to form a spark gap withthe casing and open the circuit through the other electrodes.

LOUIS HIRSCH.

